U.S. patent number 6,835,760 [Application Number 10/054,211] was granted by the patent office on 2004-12-28 for use mixtures as impression or doubling compositions in the dental area.
This patent grant is currently assigned to Heraues Kulzer GmbH & Co. KG. Invention is credited to Michael Freckmann, Matthias Schaub, Holger Urbas.
United States Patent |
6,835,760 |
Schaub , et al. |
December 28, 2004 |
**Please see images for:
( Certificate of Correction ) ** |
Use mixtures as impression or doubling compositions in the dental
area
Abstract
A dental impression or doubling composition comprising
alkoxysilyl-functional polyethers, having 20-95% polyether groups,
0.2 to 25% SiR.sup.1 R.sup.2 R.sup.3 groups and 0-10% urethane or
urea groups, and a mixture comprising water and organic or
inorganic acids, or both.
Inventors: |
Schaub; Matthias (Dusseldorf,
DE), Freckmann; Michael (Koln, DE), Urbas;
Holger (Krefeld, DE) |
Assignee: |
Heraues Kulzer GmbH & Co.
KG (Hanau, DE)
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Family
ID: |
7672193 |
Appl.
No.: |
10/054,211 |
Filed: |
January 22, 2002 |
Foreign Application Priority Data
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Jan 29, 2001 [DE] |
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101 04 079 |
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Current U.S.
Class: |
523/109;
433/228.1; 528/28 |
Current CPC
Class: |
A61K
6/90 (20200101) |
Current International
Class: |
A61K
6/10 (20060101); A61K 006/10 (); A61C 005/00 () |
Field of
Search: |
;523/109 ;528/28
;433/228.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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44 39 769 |
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May 1996 |
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DE |
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199 42 467 |
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Apr 2001 |
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DE |
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0 269 819 |
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Jun 1988 |
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EP |
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0 939 107 |
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Sep 1999 |
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EP |
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Primary Examiner: Yoon; Tae H.
Attorney, Agent or Firm: Norris McLaughlin & Marcus
PA
Claims
What is claimed is:
1. A dental impression or doubling composition, comprising A)
alkoxysilyl-functional polyethers with linear or branched main
chains with an average molecular weight (Mn) of 800 to 20,000,
containing 20 to 95 percent of polyether groups and 0.2 to 25
percent of SiR.sup.1 R.sup.2 R.sup.3 alkoxysilyl groups, in which
R.sup.1, R.sup.2 and R.sup.3, independently of one another, are
hydrogen, alkyl or alkoxy, and 0 to 10 percent of urea groups;
wherein component A) is free of urethene groups; and B) a mixture,
containing water and organic acids, inorganic acids or both in a
ratio by weight of 1:0.01 to 1:40.
2. The dental impression or doubling composition of claim 1,
wherein component A) has a branched main chain.
3. The dental impression or doubling composition of claim 1,
wherein component A) has an average molecular weight (Mn) of 1500
to 15000.
4. The dental impression or doubling composition of claim 1,
wherein component A contains 2 to 15% --SiR.sup.1 R.sup.2 R.sup.3
alkoxysilyl groups.
5. The dental impression or doubling composition of claim 1,
wherein components A) and B) are offered in tubes, tubular bags or
double cartridges.
6. A method for preparing a dental restoration which comprises
preparing said dental restoration with a dental impression or
doubling composition comprising A) alkoxysilyl-functional
polyethers with linear or branched main chains with an average
molecular weight (Mn) of 800 to 20,000, containing 20 to 95 percent
of polyether groups and 0.2 to 25 percent of SiR.sup.1 R.sup.2
R.sup.3 alkoxysilyl groups, in which R.sup.1, R.sup.2 and R.sup.3,
independently of one another, are hydrogen, alkyl or alkoxy, and 0
to 10 percent of urea groups; wherein component A) is free of
urethane groups; and B) a mixture, containing water and organic
acids, inorganic acids or both in a ratio by weight of 1:0.01 to
1:40.
Description
The invention relates to the use of mixtures as impression or
doubling compositions in the dental area.
Impression compositions, which are used in the dental area, are
known (cf. R. G. Craig, Restorative Dental Materials, The C. V.
Moosbe-Comp. St. Louis, Toronto, London, 1980, page 1979 ff). Such
materials must satisfy high requirements. 1. Pleasant odor and
taste and an esthetic appearance. 2. The compositions may not
contain any toxic or irritating components. 3. The compositions
must have a shelf life of several months. 4. It must be possible to
produce the compositions economically and the impression must be
precise. 5. The compositions must be easily handled. 6. The curing
characteristics must correspond to clinical requirements. 7. The
cured compositions must be elastic and, when stressed in tension,
must not be deformed permanently. 8. The cured compositions must
have a sufficient compressive strength and must not break. 9. At
room temperature and normal humidity, the cured compositions must
be dimensionally stable until, after an appropriate time, accurate
plaster impressions can be prepared. 10. The cured compositions
must not cause any damage to the plaster and must be compatible
with other impression compositions.
The impression compositions, which are based on
alkoxysilyl-functionalized polyethers, are described in EP 0 269
819 B1.
The use of mixtures is disclosed there, which contain A) a
polyaddition product, containing ether, urethane, and urea groups
and terminal alkoxysilane groups, with a predominantly linear
molecular structure, exclusively aliphatic or cycloaliphatic bound
ether, urethane and urea segments, with an average molecular weight
Mn of 800-2000, characterized by the a) a 25 to 90 percent by
weight content of polyether groups, b) a 0.5 to 10 percent by
weight content of urethane groups (--NH--CO--O--), c) a 0.5 to 10
percent by weight content of urea groups (--NH--CO--NH--) and d)
terminal groups having the formula --NR--(CH.sub.2).sub.n
--SiR.sub.1 R.sub.2 R.sub.3, in which n represents the numbers 1 to
6, R represents hydrogen or --(CH.sub.2).sub.n --SiR.sub.1 R.sub.2
R.sub.3, R.sub.1 R.sub.2 R.sub.3 independently of one another
represent C1 to C4 alkoxy, the terminal --SiR.sub.1 R.sub.2 R.sub.3
alkoxysilyl group content being 1 to 25 percent by weight and B) a
mixture containing water and organic and/or inorganic acids in a
ratio by weight of 1:0.01 to 1:40 as impression or doubling
compositions in the dental area.
However, these systems do not fulfill all of the requirements,
mentioned above, to the desired extent.
These impression compositions must be synthesized especially by
expensive, multi-step methods. Moreover, these products are highly
viscous, since diisocyanates are reacted with dihydroxypolyethers,
so that there necessarily is an increase in the average molecular
weight (Mn) and, with that, also an increase in viscosity. With
that, the possibilities of formulating pasty compositions with the
polyaddition products, known from the art, is greatly limited,
since either high diluent contents or low filler contents must be
selected in order to obtain compositions, which can be processed
and therefore are not too viscous.
Finally, the impression compositions based on the polyaddition
product described in EP 0 269 819 B1, when mixed with water and
acid, have unfavorable curing kinetics, which are characterized by
a short processing time and, at the same time, by a long setting
time.
In the DE 44 39 769, synthetic products are disclosed with a
polyaddition product, containing at least one silane, ether and
urethane group, with a predominantly linear molecular structure
with aliphatic or cycloaliphatic, bound ether or urethane segments
and a number average molecular weight ranging from 800 to 20,000,
the polyaddition product having the following distinguishing
features: a) a polyether group content of 20 to 90 and especially
of 50 to 80 parts by weight, based on 100 parts by weight of
polyaddition product, b) a content of urethane groups of Formula
I
--(O--C.sub.p H.sub.2p).sub.q --O--R.sup.4 (IV) in which p is a
number from 2 to 4 and especially 3 and q represents a number of
from 1 to 100 and especially 2 to 4 and R.sup.4 represents an
alkyl, aralkyl, vinyl, vinylcarbonyl, .alpha.-methylvinylcarbonyl
or .beta.-methylvinylcarbonyl group, in which the remaining
R.sup.1, R.sup.2 and R.sup.3 groups represent methyl, ethyl or
C.sub.1 to C.sub.4 alkoxy, insofar as they are not groups defined
above,
and the synthetic materials furthermore contain at least one
catalyst for the condensation of the silane groups.
An expensive, multi-step synthesis methods, which requires a
transesterification step of commercially obtainable silanes with
compounds having the structure H--(O--C.sub.p H.sub.2p).sub.q
--O--R.sup.4 is also a disadvantage of this system. The high toxic
potential of the groups of the general formula H--(O--C.sub.p
H.sub.2p).sub.q --OR.sup.4 is a further disadvantage of this
system.
It is an object of the present invention to avoid the disadvantages
of the known impression compositions based on
alkoxysilyl-functional polyethers, that is, especially to make
available impression compositions based on commercially obtainable
or easily synthesized (preferably in one step), low viscosity
(viscosity<50 Pas) alkoxysilyl-functional polyethers, which are
distinguished by advantageous setting kinetics (that is, processing
times of 2 to 3 minutes and curing times of less than 4 minutes),
that is, by a so-called snap-set behavior (slow induction time of
up to several minutes and, subsequently, very rapid setting).
Pursuant to the invention, this objective is accomplished by a use
described in claim 1.
It is a question here of the use of mixtures containing A)
alkoxysilyl-functional polyethers with linear or branched main
chains with an average molecular weight (Mn) of 800 to 20,000,
containing 20 to 95 percent of polyether groups and 0.2 to 25
percent of SiR.sup.1 R.sup.2 R.sup.3 alkoxysilyl groups, in which
R.sup.1, R.sup.2 and R.sup.3, independently of one another, are
hydrogen, alkyl or alkoxy, and 0 to 10 percent of urethane groups
or 0 to 10 percent of urea groups, and B) a mixture, containing
water and organic and/or inorganic acids in a ratio by weight of
1:0.01 to 1:40, as impression or doubling composition in the dental
area.
In further embodiments of the invention 2. mixtures are used, the
component A) of which has a branched main chain; 3. mixtures are
used, the component A) of which is free of urethane groups; 4.
mixtures are used, the component A) of which has an average
molecular weight of 1500 to 15,000; 5. mixtures are used, the
component A) of which contains 2 to 15 percent of SiR.sup.1 R.sup.2
R.sup.3 alkylsilane groups.
Some of the alkoxysilyl-functional polyethers, which are used
pursuant to the invention, such as the MS polymer of the Kanaka
Corporation, are commercially available. These are polypropylene
oxide derivatives, which are functionalized with
methyldimethoxysilyl groups (such as MS Polymer S303H).
Furthermore, polyethers, which are used pursuant to the invention,
can be synthesized in that linear or branched polyether polyols or
linear or branched, amino-terminal polyethers are reacted with
suitably functionalized alkoxysilanes and optionally with
polyisocyanates at temperatures of 20.degree. to 150.degree. C. The
use of a catalyst may be necessary for this reaction.
Suitable for the preparation of the inventive
alkoxysilyl-functional polyethers are, for example, polyether
polyols, which are known from the production of polyurethanes (for
example, Ullmann's Encyclopedia of Industrial Chemistry, vol. 21,
pp. 665 to 717, VCH Publishers Inc., 1992 or U.S. Pat. No.
5,672,652). These are compounds, which are synthesized by the
polymerization of epoxides such as ethylene oxide, propylene oxide,
butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin
with themselves in the presence, for example, of BF.sub.3, or by
the addition reaction of these epoxides, optionally in admixture or
consecutively, to starter components with reactive hydrogen atoms,
such as alcohols, glycols, glycerin, trimethylolpropane,
pentaerythritol, sugars, ethylenediamine, diethylenetriamine, etc.
Frequently, those polyethers are preferred, which predominantly (up
to 90 percent of the OH groups present in the polyether) have
primary hydroxy groups. The polyethers, which are synthesized by
the so-called DMC catalysis, for example, with zinc
hexacyanocobaltate (U.S. Pat. No. 3,278,457), have especially
proven their value. In a preferred embodiment, the polyether
polyols used have a molecular weight (Mn) of 1000 to about 15,000
and are distinguished by a hydroxy function not the of about 1.5 to
4.
Furthermore suitable for the synthesis of the inventive
alkoxysilyl-functional polyethers are so-called amino-terminated
polyethers, which are also known from the production of
polyurethanes. The amino-terminated polyethers are obtained
starting from polyether polyols by exchanging the hydroxy groups
for ammonia or primary amines (for example, U.S. Pat. No.
3,847,992). For the synthesis of the amino-terminated polyethers,
the polyether polyols, listed above, can be used in principle as
starting materials. In a preferred embodiment, the amino-terminated
polyethers used have a molecular weight (Mn) of about 500 to about
15,000 and an amino functionality of about 2 to 4.
Suitable functionalized alkoxysilanes for the synthesis of the
inventive alkoxysilyl-functionalized polyethers are distinguished
by the following structure:
In which X represents a group capable of reacting with a hydroxy or
amino group n represents a number from 1 to 8, and R.sup.1, R.sup.2
and R.sup.3 independently of one another represent hydrogen, alkyl
or alkoxy. Preferred alkoxysilanes are
3-isocyanatopropyltriethoxysilane and
3-isocyanatopropyltrimethoxysilane.
Suitable polyisocyanates are the aliphatic systems, known from
polyurethane chemistry, such as ethylene diisocyanate,
tetramethylene diisocyanate, hexamethylene diisocyanate,
dodecamethylene diisocyanate, cyclobutane-1,3-diisocyanate,
cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate,
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane
(isophorone diisocyanate),
N-isocyanatohexylaminocarbonyl-N,N'-bis-isocyanatohexyl) urea,
1,1-methylene-bis-(4-isocyanatocyclohexane),
4,4'-diisocyanatodicyclohexylmethane,
2,4,6,-trioxo-1,3,5-tris(6-isocyanatohexyl)hexahydro-1,3,5-triazine
or
2,4,6-trioxo-1,3,5-tris(5-isocyanato-1,3,3-trimethylcyclohexylmethyl)hexah
ydro-1,3,5-triazine.
Preferably, cycloaliphatic or mixed aliphatic-cycloalipathatic
polyisocyanates are used for the inventive method. Particularly
preferred is
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane
(isophorone diisocyanate).
Suitable catalysts for the synthesis of the
alkoxysilyl-functionalized polyethers, used pursuant to the
invention, are also known from polyurethane chemistry (for example,
Ullmann's Encyclopedia of Industrial Chemistry, vol. A21, pp. 665
to 717, VCH Publishers Inc., 1992). These catalysts are, for
example, Lewis bases, such as 1,4-diazabicyclo(2.2.2.)octane
(DABCO) or 1,8-diazabicyclo(5.4.0)-7-undecene (DBU) or Lewis acids
such as dibutyl tin dilaurate (DBTL) or tin dioctoate. The
catalyst-free synthesis of the alkylsilyl-functionalized
polyethers, used pursuant to the invention, is preferred.
By mixing alkoxysilyl-functionalized polyethers (component A) with
water and organic and/or inorganic acids in a ratio by weight of
1:0.1 to 1:40 (component B), elastomeric products are obtained,
which can be used in an outstanding manner as impression or
doubling compositions in the dental area.
Component A as well as component B may contain further conventional
auxiliary materials or additives for formulating pasty products.
Auxiliary materials and/or additives are understood to be, for
example, diluents, such as aromatic or aliphatic hydrocarbons,
alcohols, ethers, polyethers, esters, polyesters, fillers such as
quartz powder, cristobalite powder, calcium sulfate, diatomaceous
earth, silicates, precipitated or pyrogenic, silica with or without
a coated surface, additives, dyes, colors, fragrances, flavorings,
emulsifiers and stabilizers.
Preferably, components A and B are offered for use in tubes,
tubular bags or double cartridges.
Elastomeric impressions, based on the inventive impression
compositions, can be prepared in ways known to those skilled in the
art. Components A and B can be mixed by hand or by automatic mixing
systems. For the user, the parameters of processing time and
setting time are very important parameters of an impression
material. It is desirable that, for a practical processing time,
which generally falls within the range of a few minutes, a setting
time can be adjusted to a value, which is only slightly longer than
the processing time. The setting characteristics of elastomeric
impression compositions can be quantified, for example, by means of
rheometric methods. The amounts of the storage module G' (as a
measure of the elastic portion of an impression material) and of
the loss module G" (as a measure of the viscous portion of an
impression material) can be determined by measurements by means of
oscillation rheometry. Furthermore, the equation, tan
.delta.=(G"/G') applies. By observing the course of the curing as a
function of the time elapsed since the start of the mixing by means
of oscillation rheometry, the times can be determined at which
G'=G" or .delta.=45.degree. (t.sub.1) or .delta.=10.degree.
(t.sub.2); in this connection, t.sub.1 can be interpreted as the
processing time and t.sub.2 as the curing time of the impression
material. The ratio t.sub.2 /t.sub.1 can be regarded as a quantity
for characterizing the setting kinetics. The closer this ratio is
to 1, the more advantageous is the setting behavior in the
direction of "snap-set". For impression compositions based on or
alkoxysilyl-functional polyethers corresponding to the state of the
art, the t.sub.2 /t.sub.1 ratio of is found to be of the order of
1.7 to 2.0. On the other hand, in the case of the inventive
systems, a ratio of t.sub.2 /t.sub.1 of 1.2 to 1.3 can be
achieved.
It is extremely surprising that the inventive impression
compositions are distinguished by setting kinetics, which are
significantly more advantageous than those of impression
compositions of the state of the art.
EXAMPLES
Example 1
General Method for the Synthesis of Alkoxysilyl-functionalized
Polyethers from Polyether Polyols.
A polyether polyol (300 g) is dehydrating for one hour at 10 mbar
and 100.degree. C. Subsequently, one mole of
isocyanatopropyltriethoxysilane per mole of hydroxy group is added
followed by 1 drop of dibutyl tin dilaurate. The mixture is stirred
at 100.degree. C. until isocyanate groups can no longer be detected
(see Table 1, A1 to A5).
Example 2
Synthesis of Alkoxysilyl-functionalized Polyethers from Polyethers
with Terminal Amino Groups
General Method:
A polyether (300 g) with terminal amino groups is dehydrated for
one hour at 10 mbar and 100.degree. C. After the polyether has
cooled to 60.degree. C., a mixture of
isocyanatopropyltrialkoxysilane, isophorone diisocyanate and
cyclohexyl isocyanate is added dropwise over a period of 30
minutes, so that the molar ratio of amino groups to isocyanate
groups is 1:1. The mixture is stirred at 60.degree. C., until
isocyanate groups can no longer be detected (see Table 1, A7 to
A11).
Comparison Example
The synthesis of a linear poly(ether-urea) polyaddition product of
EP 0 269 819 B1, Example 3, requires two steps and leads to a very
viscous end product (see Table 1, V1).
Example 3
Formulation of the Catalyst Component B
32.2% dihydroxy-polypropylene oxide (MW 2000) 2.8% paraffin 0.3%
emulsifier 59.2% quartz powder 3.2% pyrogenic silica and 2.3% of a
16 percent aqueous solution of p-toluenesulfonic acid hydrate
are mixed in a mixer in the sequence given to form a homogeneous,
pasty composition. The mixing time is 30 minutes at 50 rpm.
Example 4
The polyether with alkoxysilyl terminal groups, which is described
in Examples 1 and 2, and commercially obtainable polyethers with
terminal alkoxysilyl groups are mixed intensively in a ratio by
weight of 1:1 with the catalyst component B. After a few minutes, a
product is obtained, which has been cross-linked into an elastic
material.
Example 5
Formulation of a Dental Impression Composition:
19.1% A10 19.1% diluent 54.5% filler (quartz powder) 4.0% paraffin
and 3.8% polyethylene fibers
are homogenized into a pasty composition in a mixer (component
A).
Components A and B are mixed intensively for 30 seconds in a ratio
by weight of 1:1.
The physical characterization of the impression composition
according to ISO 4823 provides the following results,
Viscosity 153.6 Processing Time (min) 1.8 Curing Time (min) 2.4
Curing Time/Processing Time 1.3 Recovery after Deformation (%) 97.7
Dimensional Change (%) 0.45 Shore A Hardness (1 h) 52
Comparison Example
19.1% V1 19.1% diluent 54.5% filler (quartz powder) 4.0% paraffin
and 3.8% polyethylene fibers
are homogenized to a pasty composition (component A) in a mixer
Components A and B are mixed intensively for 30 seconds in a ratio
by weight of 5:1. Investigations of the setting kinetics and of the
physical characterization of the impression composition by the
method of ISO 4823 gave the following results:
Viscosity (23.degree. C., 3s 1) (Pas) 275 Processing Time (min) 2.2
Curing Time (min) 3.8 Curing Time/Processing Time 1.7 Recovery
after Deformation (%) 98 Dimensional Change (%) 0.36 Shore A
Hardness (1 h) 51
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